Hey. I wasn't whinning about the problem with the fork, I just wanted to post an update as to the frequency of the problem with the Super Fatty Air Cartridge Fork. The last time I had it rebuilt by Cannondale, back in late summer early fall last year it leaked oil constantly until it had about a one inch drop or play at the top end when in lockout. My shop guy said it was low on oil so I learned how to fill it myself. Funny, it quit leaking after that. Now it's been about six months with only maybe a dozen rides in that time period and it's cluncking at the top end. It hits pretty hard too. I weigh 180lbs. I put enough air in it so that it doesn't bottom out and I get just a little sagg when I sit on the bike. The terrain I ride is mostly singletrack with switchbacks and log obstacles to hop over. Some fast fire roads and of coarse the occassional washed out rut on the trail. No rock gardens or jumps. I have a Specialized FSR Enduro for that ruff stuff. And I tend to ride it alot more than the F700. Getting older and riding the trails gets harder on the back when you ride a hardtail. But, the bike is a 2001 and still looks faily new and in great shape so that should tell you I don't abuse it. This fork is just a piece of junk. I thought of putting the new Magura cartridge in it but I think that it's around $350 but I haven't heard any reviews about it. I would spend the money in a minute if I knew most of the maintenance issues would end. I took it apart again today and guess what I found loose inside. There's a small O-ring about 1/2" diameter laying in the bottom. I can't figure out where it goes. With no drawings available I'll never figure it out either. Unless someone here knows, it's going back to Cannondale again.

That O ring most likely came from the bottom of the cartridge where it threads into the fork. That is the only readily accessible O ring in there. All the others are internal to a certain degree. It sounds as though whoever did your work did not replace the seals all around. As many have said here, this is one of the more "ride it and forget it" forks made by Cannondale. That said, if you can get the cart out yourself, order an "All seal" kit from Cannondale, through your LBS, and install all of it you can. If your work is good, and all the internals are in GREAT shape, no nicks or scratches in the shaft etc, yopu should be fine from there. I have had forks that leak oil after a rebuild, and replacing the seals will square it away. Sorry to hear of your troubles, that should not be the case, and underscores my point about shops being able to service them in the field. If Cannondale has to handle 90% of the forks they have ever made, cause their shops to a large degree suck, than you can bet Cannondales service will suck too, based on volume related pressures. Good luck!

That O ring most likely came from the bottom of the cartridge where it threads into the fork. That is the only readily accessible O ring in there. All the others are internal to a certain degree. It sounds as though whoever did your work did not replace the seals all around. As many have said here, this is one of the more "ride it and forget it" forks made by Cannondale. That said, if you can get the cart out yourself, order an "All seal" kit from Cannondale, through your LBS, and install all of it you can. If your work is good, and all the internals are in GREAT shape, no nicks or scratches in the shaft etc, yopu should be fine from there. I have had forks that leak oil after a rebuild, and replacing the seals will square it away. Sorry to hear of your troubles, that should not be the case, and underscores my point about shops being able to service them in the field. If Cannondale has to handle 90% of the forks they have ever made, cause their shops to a large degree suck, than you can bet Cannondales service will suck too, based on volume related pressures. Good luck!

Good news. I tore down the fork this morning. I found that the rings, seals, o-rings had somewhat expanded or swelled and were barely doing their job. Now, either Cannondale did not replace the seals when they rebuilt it or the fork oil I used the last time I topped it off destroyed em. I tend to think it may be the oil. I say that because I used a syringe for filling and the rubber plunger swelled. I got another new syringe and it did it again. Why would fork oil do that? I got the oil from a motorcycle shop. Anyway, I went to the bike shop and bought a new seal kit and some different oil. I figured out where that small 3/8" to 1/2" o-ring went. There is a plastic ring that fits on the top of the spring in the air chamber. The o-ring fits between that plastic piece and the bottom of the oil chamber. I got it all together and bled and it works as good as new. I got the bearings greased and now it's ready for action again. The seal kit was only $8. Why then does the Factory charge so much? As I remember Cannondale charges something like $65 for that. Then the bike shop added their take $45 for putting the fork back on the bike. I'm glad I learned how to do the job myself but without the documentation it was stressfull.

Why then does the Factory charge so much? As I remember Cannondale charges something like $65 for that. Then the bike shop added their take $45 for putting the fork back on the bike..[/QUOTE]Cool, glad it all worked out. I am not sure why the oil swelled your seals. The recommended oil is Golden Spectro, which is Moto oil, so , go figure???The factory charges so much, for the same reason dogs lick what they do, cause they can. It's obscene that they would do that to someone over a barrel, no shop in the area to fix your shock? We'll bend you over then, cause hey, someone has to! Then your shop charging $45 to install a fork, which takes about 5 minutes?? I am all about folks making a living wage, and shops charging rates comensurate with the level of professionality that a good mechanic deserves, but come on, let's also use our heads, hmmm, 10 minutes tops, TOPS, X $45= $270 hourly rate, I think there is an issue here. Fully certified Ferrari mechanics don't command that sort of price. You can do everything else, a fork removal will be cake. Don't give those folks a dime, they don't deserve it! Man, am I surly in the morning=

First of all, excellent job by Nigeyy on a tricky service. I'm a fully qualified auto technician and would love to strip down my fork next time it needs servicing. I have to say though the guy who serviced it in May only charged $50 including return shipping and I was very impressed with his work, sending me the old parts, a sheet with the work carried out, another sheet with maintanece instructions and set-ups, etc. If you do the sam job a number of times you will get very good at it - or very sloppy! As you've read here there are no big springs going to fly out and disappear down the back of the garage, just take your time and you can do it.

You need size specific shaft clamps and a bullet tool for re=assembly. That nut on top is press fitted and it's not supposed to come off. If you never did it I would highly suggest you send it in for a rebuild, because one wrong move and you will completely eff it up....a scratch on the shaft and you'll have constant oil leaks....

anyone recognize this Headshok cartridge?

I am new to the forum so I am not allowed to start a new thread without 5 posts. Instead I''l try to attach my question to this old topic.

I have researched this for hours. I have a C. F600 which I bought in '04. The Headshok recently went south so after viewing several web sites that demonstrate repairs I decided to tackle this (replace o-rings) on my own. Bottom line; after disassembling the unit I find it looks quite different from all the examples I have previously viewed. I seem to be close to being able to do this if I could only get a couple of questions answered. Instead of inquiring at this point I shall just ask if anyone knows of this particular cartridge and, if so, I shall proceed.
PS. There is no spring nor elastomer evident.

Wow, thanks Mac, that's it! It is the first real foto of that particular model I've seen after hours of googling. The others have had colored cannisters or different configurations at the base.

You are correct on the spring. Shortly after I posted this I turned the fork upside down and, sure enuf, out fell the spring and then the entire air cartridge. Sweet!

My question then:
How can one remove the top white plastic threaded plug of the oil chamber through which the damper rod passes? I suspect there is an o-ring inside of it which could be a source of an oil leak. That plug is located between the large black stem cap above and the series of "washers" of the lockout valve (halfway down the rod) below. Neither the black cap nor the lockout mechanism seem to be removable from the rod. Since I had lost damper oil I would like to replace all the critical o-rings where a leak to outside of the cartridge could occur and the top plug seems critical. Every movement of the damper rod involves that passage thru the plug.
Did your service include replacing o-rings including that possible one inside the top plug?

All I did was an inspection, clean and oil change. I didn't bother changing any seals as there were no leaks or problems with the fork.. in situations like this I like to follow the golden rule - 'if it an't broke, don't try and fix it'

To get access to the upper oil cap you have to separate the damper shaft..

Please be aware that you absolutely require specialist tools for this particular job or else you will make a dog's dinner out of your damper shaft.. Do not DIY a tool to hold the damper shaft.. just get the right tool for the job because one small scratch on the shaft and your in a whole heap of trouble.. and expensive trouble at that..! The tools are inexpensive compared to a new damper..

You need 1/2" shaft clamps.. this tool is essential to hold the shaft safely without scratching it..

Also, I would recommend you do your homework thoroughly before trying this.. so you are aware of the steps involved and the risks.. I'm not qualified or experienced enough to talk you through it so I don't want to give you the wrong advice..

I hear you loud and clear re: causing damage. However I don´t consider my Headshok sacred and if I screw it up I´ll either go ¨shockless¨ or replace it with another brand fork. I just don´t like the idea of being held captive by Cannondale; by their way of restricting access to repair information and proper tools. This is not rocket science.

I may just replace the easily accessible o-rings and call it good but I am curious about the assembly and especially since Cannondale has make it a top secret that only a few select and priviledged share. Thanks to people like you the ridiculous secrecy is somewhat open.

That said, and a hearty THANKS for the tool links, could you tell me just where it is the damper shaft separates into two? Is it at the top black steering tube cap or just below the lock out mechanism half-way down the shaft? I assume one part unscrews against the other.

FWIW, it's not ridiculous. The consuming public at large, often is though.

By not making all info public, they protect the great unwashed (a little bit), from their own overzealous, cheap minded DIY efforts, which invariably ends with them calling Cannondale and screaming warranty, or the thing falls apart on the trail, they lawyer up, and Cannondale has to defend themselves.

Not saying anyone in particular here would do that, but I can't tell you the number of mangled piles of parts I get in boxes from hand wringing anxious riders who tried to DIY....

So I ride my Cannondale knowing that it has a rather delicate fork mechanism with a rather high probability of failing, will cost a rather large sum of money, hassle and time to get fixed and for which I will be considered guilty of trespass if I want/try to maintain it myself. So much for self reliance and independence. What kind of sport is this?

You know, that logic could be applied to about any product out there. Hands off - too dangerous to do yourself - let us take care of it, or else. How about a flat tire?

I am aware of the risks of messing up the repair and am willing to pay the consequences. Hey, more money for the bike shop. But I question the idea that this piece of equipment is too sophisticated for me to deal with (given the proper diagrams and tools) or that repairs of equipment I have paid dearly for (> $1000 in ´04) become an ongoing financial drain with just average usage.

Sorry but I stick with my opinion that $150 to have repaired/maintained a rather simple device is excessive and unnecessary.

[QUOTE=fredf;9837988
That said, and a hearty THANKS for the tool links, could you tell me just where it is the damper shaft separates into two? Is it at the top black steering tube cap or just below the lock out mechanism half-way down the shaft? I assume one part unscrews against the other?
Fred[/QUOTE]

Yes, they are....the lower damping shaft has a slots for an open end wrench...(a special...really flat one)....hold the top part of the damper shaft with shaft clamps and unscrew the lower one....once separated you will be able to take it completely apart....I used to hold the lower shaft with a shaft clamp and and used an adjustable wrench on the lockout knob on top to undo the shafts...I was told that this might damage the lockout, but if done carefully enough it will be ok and I never had issues because I did it that way...make sure you use appropriate loc tite when you reconnect the damper shafts!

cdalemainiac:
That is what I suspected re: the rod disassembly. Thanks for confirming it. Now I can access all the critical parts for o-ring changes which should solve the damper oil leak that has rendered my Headshok useless. Since the bike has low only highway miles everything inside the shock looks brand new so I guess the rings just deteriorate over the years regardless of usage.

MendonCycleSmith:
Nope; I am going to vote Libertarian.
My local shop quoted me at least $150 to send the shock to CDale. They won´t touch it themselves (why is that; intimidation?) and they are the ones that sold me the bike.
Me the whiner? I began by soliciting advice for doing my own repair and was happy learning what I needed to know from a couple of members. I suspect you could have also helped but instead apparently you took my negative comments re: Cannondale personally. Sorry about that but after reading scores of complaints about CDale´s policies and practices I know I am not speaking out of line.

MendonCycleSmith: I suspect you could have also helped but instead apparently you took my negative comments re: Cannondale personally. Sorry about that but after reading scores of complaints about CDale´s policies and practices I know I am not speaking out of line.

Sorry, just way overextended, too much on my plate at the moment. I have personally answered these same questions more times than I can count on here, hence the sticky at the top, with all manner of Tech threads, all in one place. There is also scads of threads scattered about this forum, and searching will turn them up.

It's frustrating to have yet another person blame Cannondale for not making it easy to DIY, when I see so many of the DIY efforts turn to crap in a box, and hatred for the brand.

Too many people are cheap, won't buy the tools because they are just positive that the Vice Grips will work just as well, then use improper parts, damage things without knowing it, then go on the internet and blame the brand, instead of themselves for screwing it up.

Thanks for the apology. Obviously you are an important contributor to this forum - I would rather be with you than against you.

The info you have pinned to the start of this topic is useful but, again, is not that of my particular cartridge. I have not run into fotos or diagrams of mine yet.

What I really need is a detailed breakaway diagram of my damper components. The verbal descriptions are useful but often lack some critical detail. It appears that the CDale manuals with drawings that were previously accessible to the public are no longer so. I guess I shall just have to proceed one tiny step at a time asking questions and be glad that I can get answers at all.

The info you have penned to the start of this topic is useful but, again, is not that of my particular cartridge. I have not run into fotos or diagrams of mine yet.

It's the same function wise as any of the lockout dampers of the era. There are two types with oil, the 5 position damper dial, and the lock out. They may vary slightly in appearance, but are the same at heart.

You'd need an arbor press and the correct tooling to push the damper shaft apart, and reassemble. The nut at the top holds it all together, and is pressed on, it does not have threads.

You'd need an arbor press and the correct tooling to push the damper shaft apart, and reassemble. The nut at the top holds it all together, and is pressed on, it does not have threads.

Only if he wants to remove the threaded top cap though....the damper shafts are connected via threads.....the nut will only turn so much (lock out disengaged) and you will be able to undo the shafts....once apart the rebound rod will be accessible, along with all other parts in need of new o-rings.
Always worked fine on my fatty cartridges and my dlr2 damper as well if not put together correctly though you will end up with your lockout in reverse order like somebody here on this forum mentioned before. Despite what some folks say this is possible as it happened to me as well.
Meaning: counterclockwise=locked out, clockwise=open